Table 2.

Analyzed activity of phytase (FTU/kg) in the starter (1–15 d of age), grower (16–29 d of age), and finisher (30–41 d of age) diets.¹

Dietary treatments	Starter	Grower	Finisher
1) Negative control (NC)2	65	<50	<50
2) NC + 500 FTU/kg	417	519	641
3) NC + 1,500 FTU/kg	1,250	1,250	1,490
4) NC + 4,500 FTU/kg	3,313	3,350	3,960
5) NC + 13,500 FTU/kg	12,480	13,710	12,690
6) NC + 40,500 FTU/kg	36,640	41,290	42,070
7) Positive control (PC)2	695	238	267
8) PC + inositol3	65	<50	<50

¹One unit of phytase activity (FTU) is defined as the quantity of enzyme to liberate 1 μmol of inorganic phosphate per minute from 0.0051 mol/L sodium phytate at pH 5.5 and 37°C.

²The negative control diet was formulated to contain 0.165 and 0.150% lower calcium and phosphorus, respectively, than the positive control diet.

³Inositol supplementation was calculated based on the maximum inositol liberation from the diet containing the highest phytase concentration.